Odd behavior

My big sassy "top of the pecking order" hen was a little out of it yesterday. She hung back from the group while free ranging, was listless and puffed up. She obviously wasn't feeling well. Her comb and waddles look great- rich red, plump, very large with a nice subtle sheen. I did notice that her feet looked puffy! It was so odd! She looked the way a person does when retaining water around their ankles. Both of her feet were thicker (legs, ankles, and toes) and had tiny puffy "rolls"of skin scrunching up while she stood, which is unusual. I kept comparing her legs to the other chickens' to make sure I wasn't just seeing things- but nope! Her legs were swollen! I picked her up (which is also strange cause she's normally super independent) and she felt fat and healthy- no bones or squishy abdomen. Her legs didn't feel any different.

She is starting to molt, but I've never seen a chicken with PMS (Pre-molt symptoms) (...just made that up). She looked back to her old self today. Any ideas on what happened or what might be wrong?

I'm not entirely certain of her age. I bought her from some folks who were moving last fall- they said she's been from that year's clutch, implying that she is now a year and a half old. I have three NH Red hens who lay brown eggs and between three of them I usually get 2 a day, once in a rare while I'll get 3, so I think they're all laying.

She was lethargic and fluffed up again today. I picked her up again when she went to roost and felt her to make sure. No squishy abdomen, no bony breast. She's missing nice patches of feathers now, molt is just about in full swing! Her legs still seem puffy to me...

Next time I see her poop I'll run and look at it. She isn't as excited about food as normal- usually she's an oinker! She's the heaviest of the girls, but she's physically just HUGE! I'll spend some time monitoring her tomorrow. I was gone most of today so I didn't get to check in on her til dusk.

Her feces is a little on the runny side, but not too alarming. She dropped all her tail and bum feathers in a day or two and has a big naked patch on one wing. This molt is less than graceful!

I had family over yesterday and took them out to feed the chickens. My mother (who knows NOTHING about chickens) immediately said "What's wrong with her legs?"

So no, it's not just me. Her legs are definitely swollen! She's still acting a bit under the weather, fluffing up and such. She's gone form top to bottom of the pecking order. Today I tried to hand feed her and she didn't want the food and was sucking in air kind of wheezingly. I swear her comb looks a bit dark, which I know is an oxygen problem, but it could just be me...

There are new feather shafts coming in where she dropped feathers, so it's not from pecking or anything.
I've checked the girls several times for mites and haven't found any.

I don't think she's laying. I'm getting 2 brown eggs a day out of 3 NHR chickens who lay brown eggs. My other girls lay white and blue. I haven't had a day where I got three browns in quite awhile. If she's molting this is to be expected I guess. The only thing making me raise an eyebrow is that the last few days my brown eggs have been rough shelled, unevenly colored, and almost "dry" feeling on the outside. Like fine sand paper, and the eggs almost look like they've been sitting in the sun and got bleached out a bit on one side (which of course couldn't have happened). My other girls are laying normal looking white and blue eggs.
I originally had 4 NHR, but one passed away this spring from internal laying. They were all factory hens from the same clutch.

So here's a few shots of her legs. Sorry for being untimely :/ It's been super chaotic.

They don't look swollen anymore, but I had a friend second the leg mites suggestion. I feel like the grey spots are new. I never really looked at her legs, but I don't seem to recall them having grey spots. My friend also commented that the pink webbing was unusual. This is something that she's always had. I have a rooster whose legs are extremely pink. I thought it was normal coloration for some chickens?

Anyways, she's been perkier this last week. I've been giving them oodles of raw pumpkin goo and seeds since I've been cooking. Coincidentally I've read that raw pumpkin seeds can be a natural parasite preventative for chickens.

I'm still wondering though, if this could be scaly leg mites, what should I be looking out for? What precautions should I take?